Many individuals who use chairs for long periods do not prefer to sit in a totally stiff chair. In response to this, manufacturers have produced adjustable chairs which provide individuals who use them with an added degree of comfort compared to stiff non-adjustable chairs. To accommodate these individuals, the adjustable chairs have numerous fine tuning adjustments. The adjustments can include devices for varying a height of the seating surface, varying the position of a seat back or adjusting the tension spring on a seat back for more or less support when an individual reclines.
Chairs which use these current seating designs may have to be constantly readjusted to allow an individual to position him/herself to a desired position. This may require a user to dismount the chair and fine tune the chair position to a desired configuration. This fine tuning may lead to further discomfort, and can impact the stability of the chair. As a result, the user must fine tune the chair again to a new setting to overcome these shortcomings. Over time, these chair settings may vary, requiring the user to again reset the chair to a desired configuration. As there is a constant need to fine tune the chair components, most users ignore the shortcomings of the chair configurations and merely use the chair in a non-optimal configuration. Such use in a non-optimal configuration can lead to significant problems such as worker fatigue and/or medical problems.
Another significant drawback of certain chair designs is that production of chairs which have numerous fine tuning adjustments is a complex procedure, increasing the overall production time and cost of the chair. Moreover, chairs which have numerous parts are more prone to fail, decreasing the overall service life.
Certain conventional chairs are believed to have a seat and a seat back that are positionally affixed to each other by connecting frame elements and that are cantilevered relative to a bottom support portion of a frame so that the seat and seat back are constrained to move in unison with each other relative to the bottom support portion of the frame, i.e., to the floor. Due to, e.g., ergonomics, user comfort, etc., there is believed to be a need for a chair in which the seat back and the seat are movable independently of each other relative to supporting frame members and to the floor.
There is believed to be a need for a chair which may provide a user with a supportive seating surface, but which remains flexible when a user shifts position, such as when the user rests against a chair back. There is also believed to be a need to maintain the amount of flexure for the chair such that a user may easily find a comfortable seated position.
There is believed to be a need for a chair design which may alleviate a user from having to continually finely adjust a chair position to maintain a comfortable configuration over time.
There is believed to be a further need to provide such a chair that may be inexpensive to manufacture and which may have a long service life.